Method of making a focused multicell



Jan. 24, 1956 v. J. SCHAEFER METHOD OF MAKING A FOCUSED MULTICELL Filed Nov. 23

Ifiventor:

e g 6% a m Tr m s A L w H mm V 2,731,713 METHOD OF MAKING A FOCUSED MULTICELL Vincent. J; Sc'h'ae'fer, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application November 23,1951, Serial No. 257,694 8 Claims. or. 29-423 This invention relates to the met'hod of making a focused multicell; More particularly, the invention relates to a method for preparing a multicell in which. all of the cell units are so oriented that they are focused at a point a predetermined distance from the unit.

A multicell is a the manner of the cells making up a honeycomb. 'The group of cells in a multicell may have their axes positioned in parallel alignment/but this is not necessary. in certain optical apparatus, it is very desirable to have a multicell in which the axes of all of the individual cells are focused on a sing-le point. In the past the preparation of a multicell made up of a great many very minute cells which have their axes focused on a single point has represented a very difiicult problem.

it is an object of this invention to provide a method forproducing a focusing multicell made of many very small individual cell units. Another object of the invention is to produce amulticell heating element having a great deal of radiating surface area.

Another object of the invention is to provide a method for fabricating a focusing multicell wherein there is very little likelihood that any of the cells will buckle during fabrication.

Other objects of the invention will be apparent from a perusal of the following specification considered in conjunction with the attached drawings wherein:

Fig. 1 is a diagrammatic view of the initial step followed in producing a multicell;

Fig. 2 illustrates the forming step performed on the multicell; I

Fig. 3 illustrates a s'intering operation followed in fixing the cells in position;

Fig 4 illustrates the step of filling the individual eel-ls with liquid;-

Fig. 5 illustrates a freezing uicl in the cells is solidified;

Fig. 6 illustrates the step followed in focusing the individual cell units of the multicell; and

Fig. 7 shows the finished multicell of cell units in position.

In accordance with my invention, a strip of corrugated process whereby the liqstrip on top of the corrugated strip,

convex. A sintering operation will then fix and bond the individual cells together so as to retain this concaveconvex conformations. If the individual cells of the group of cells oriented somewhat in with the plurality 2,731,713 Patented Jan. 24, 1956 multicell are thin-walled and fragile, they may be filled with liquid and the liquid frozen, thereby imparting to the walls of the individual cells a considerable resistance to buckling.

The ends of the roll may then be compressed to restore the initialfiat configuration. This pressing operation realigns and reorients the axes of the individual cells so that they are focused on. a central axial point.

Referring to the drawings, Fig. 1 shows apair of rolls cross section. Strips 10 and12 are then cowound on a roll 13 where the corrugations of the strip 10 form a plurality of cells which are separated by the strip 12.

The size of the individual cells making up the multicell size of the teeth of the gears 11.

very easily by stopping the winding process when the desired diameter has been reached;

I When the multicell 13 has attained the desired diameter the strips 10 and 12 are cut and the loosely assembled roll placed upon a form 14 as shown in Fig. 2. The form 14 has a convex surface, the degree of convexity dependingupon the focal length which it is desired to have in the final multicell.- As the degree of convexity decreases, the focal length of the final multicell increases.

might tend to buckle them.

After freezing, the ice filled multicell unit is placed on an arbor press between two fiat plates as shown in Fig. 6

product is illustrated in Fig. 7.

While the strips 10 and 12 will normally be of the same material, it is not the temperature of a 300 cu. ft. room 10 F. in twenty minutes.

A multicell may be made up of very long cells (the width of the gears used for making the corrugated foil may be of practically any dimension), and the size of the gear tooth may be of any fineness down to 100 pitch or smaller. Such a multicell may be used very satisfactorily as a collimator for use in conjunction with X-rays. My

method may be used to fabricate multicells of very soft metal, such as pure lead and cadmium, by folding a foil of this substance on either side of a thin foil of steel or aluminum. When passed through the corrugating rolls, the soft material becomes intimately formed in contact with the harder core, and as a result, it is easy to make 'a strong multicell having a softer metal effectively sup- 1. The method of preparing a multicell which com- 'prises winding a corrugated strip along with a flat strip to form a roll having a plurality of cells in parallel axial alignment, deforming said roll to give it a concave configuration on one side and a convex configuration on the other, heating said roll to fix said roll in the concaveconvex position, filling said cells with liquid, solidifying said liquid, and forcing said solidfied liquid-filled roll to a flat-end configuration whereby the axes of said cells are brought to a substantially common focus.

2. The method of preparing a multicell which comprises winding a corrugated strip of metal coincidentally with a ,fiat strip to form a roll having a plurality of cells in axial alignment with the axis of the roll, forming said roll to provide a concave surface at one end of the cells and a convex surface at the other, sintering said roll to fix said concave-convex configuration, filling said cells with liquid, solidifying said liquid, and deforming said roll while the liquid is melting to flatness at the ends of said cells whereby said cells are axially focused.

3. The method of preparing a multicell which comprises corrugating a strip of bendable material, winding the corrugated strip together with a smooth strip to form a roll of cellular construction, break the cross-sectional planar alignment of the cells,

sintering the roll to fix the changed planar alignment of the cells, filling the cells with liquid, solidifying the liquid, and applying stress to said solidified liquid-filled roll whereby said cells are restored to their original crosssectional planar alignment and said cells are axially focused.

4. The method of preparing a multicell which comprises cowinding a thin corrugated metal strip with a thin flat strip to form a roll containing a plurality of thinwalled cells in parallel axial alignment with the axis of said roll, displacing sa'd cells longitudinally whereby the deforming said roll to V side of said roll at one end of said cells has a concave configuration-"and the side of said roll at the other end of said cells has a convex configuration, heating said roll to fix said cells in the concave-convex configuration, filling said cells with water, freezing said water, and pressing said roll to flatness at the ends thereof while the frozen water is melting whereby the axes of said cells are focused upon a common point.

5. A method as claimed in claim 4 wherein the metal strips are of the order of 0.001 inch in thickness.

6. The method of making a focused multicell which comprises winding a corrugated strip along with a fiat strip to form a roll having a plurality of cells in parallel relatively slidable axial alignment, deforming said roll to give a concave configuration on one side and a convex configuration on the other, heating said roll to bond the cells togetherin the concave-convex position, and forcing said bonded roll to a flattened configuration whereby the axes of said cells are reoriented to a substantially common focus.

7. The method of changing the relative axial orientation of the individual cells of a corrugated thin-walled multicell, which method comprises filling the cells with liquid, freezing t e liquid to rigidity the multicell, and deforming the multicell by an axially applied force while the frozen liquid is melting.

8. The method of preparing an axially focused multicell from a fiat cellular metal structure of the type having a plurality of open cells in relatively slidable parallel axial alignment, which method comprises applying an axial force upon said structure to deform said structure to a convex surface at one end of the cells and a concave surface at the other end, heating said structure to bond said cells in said concave-convex configuration, filling the cells with water, solidifying the water, and applying an axial force upon said structure while the solidified water is melting to deform said structure back to its original fiat configuration whereby the individual cells of the structure are reoriented in axially focused alignment.

References Cited in the file of this patent UNITED STATES PATENTS 745,759 Baehr Dec. 1, 1903 1,121,859 ,Messiter Dec. 22, 1914 1,275,785 Stratton Aug. 13, 1918 1,588,976 McBlain June 15, 1926 1,976,871 Wine Oct. 16, 1934 2,075,815 .Knox Apr. 6, 1937 2,163,590 De Ganahl June 27, 1939 2,167,215 Leary July 25, 1939 2,212,481 Sendzimir Aug. 20, 1940 2,366,141 Alderfer Dec. 26, 1944 2,393,548 'McCoy Jan. 22, 1946 2,487,257 Morgan Nov. 8, 1949 2,498,674 Graham et al. Feb. 28, 1950 FOREIGN PATENTS Great Britain Oct. 29, 1940 

